Devices using a motor typically for a hybrid vehicle, electric vehicle, or the like requires a power conversion device with excellent energy conservation. A power semiconductor module mounted with a power semiconductor element such as an IGBT (Insulated Gate Bipolar Transistor) is widely used in this power conversion device. In order to efficiently radiate heat generated when the power semiconductor element is energized with a large current, the power semiconductor module is required to be connected to a cooler, to be small, and to be structured to have excellent heat radiation performance.
For example, a semiconductor module disclosed in PTL 1 includes an insulated circuit substrate wherein a metal layer is disposed on either surface of a ceramic substrate. A multiple of power semiconductor elements is joined to one main surface of the insulated circuit substrate, while a thick heat radiating substrate made of metal is joined to the other main surface. The insulated circuit substrate is housed in a resin case, and a gel-form resin is injected, thereby forming a power semiconductor module. Further, the semiconductor module is fixed with a bolt and nut to a cooler through a heat radiating grease.
Meanwhile, a semiconductor module wherein, after a resin sealed module and a cooler are joined with solder, a gap in a region peripheral to the solder joint portion is filled with a sealing resin is disclosed in PTL 2.
Also, a semiconductor module including a metal block, a semiconductor element joined through a solder layer onto the metal block, and a resin molded portion in which the metal block and the semiconductor element are molded, wherein the metal block has a surface including a plated region and a roughened region, and the semiconductor element is mounted in the plated region, is disclosed in PTL 3.